Frequencies for emer_use variable in vehnit dataset :

  EMERGENCY |
        USE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      1,110       99.46       99.46
          1 |          3        0.27       99.73
          9 |          3        0.27      100.00
------------+-----------------------------------
      Total |      1,116      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016